Prep the Carrots: Peel, trim, and cut carrots into uniform 2-inch batons (or diagonal slices/baby carrots).
Optional Blanch: Boil carrots in salted water 2 min, then shock in ice water; drain thoroughly.
Make the Glaze: In a large skillet over medium heat, melt butter. Stir in brown sugar and honey until smooth. Add orange juice and thyme, bring to a gentle bubble.
Glaze the Carrots: Add carrots, season with salt and pepper, and toss to coat. Reduce heat to medium-low, cover, and cook 8–10 min, stirring occasionally.
Thicken the Glaze: Remove lid for last 2 min, spooning hot glaze over carrots to concentrate the sauce.
Finish: Off heat, stir in lemon zest if using. Transfer to a platter, garnish with parsley and extra thyme.